What Causes Brownish And Yellowish Discoloration In Eyelids?

I have this skin discoloration in both eyelids that s continuing to get bigger. My doctor saif it s because og high cholesterol and didn t say anything else. However, no matter what tests I do, my cholesterol, sgpt/sgot etc are all normal so I don t know what s causing this brown/yellowish discoloration in my eyelids. My dermatologist said it s also caused by high cholesterol and said it can never stop once the discoloration starts. What to do?